Rescue crews using dogs and helicopters resumed on Thursday the arduous task of combing through tons of debris for survivors from deadly mudslides in southern California. Seventeen people are confirmed dead and another 17 people are missing after a river of waist-high mud roared down hillsides in the scenic area between the Pacific Ocean and the Los Padres National Forest, according to authorities in Santa Barbara County. "Right now, our assets are focused on determining if anyone is still alive in any of those structures that have been damaged," Santa Barbara County Sheriff Bill Brown told Los Angeles television station KCAL. Some 500 rescuers using search dogs, military helicopters, and thermal imaging equipment are on scene. Search and rescue efforts have been slow as crews have to navigate through the mud, fallen trees, boulders and other debris. The devastating mudslides, which were triggered by heavy rains early on Tuesday, roared into valleys denuded by historic wildfires that struck the area last month. The debris flow from the mudslides has destroyed 100 homes, damaged hundreds of other structures and injured 28 people, said Amber Anderson, a spokeswoman for the Santa Barbara County Fire Department. Among the damaged properties were historic hotels and the homes of celebrities including television personality Oprah Winfrey and talk-show host Ellen DeGeneres, who both live in the upscale hillside community of Montecito. The US Coast Guard released footage of a couple, their two young children and two dogs being plucked from their roof and hoisted up to a helicopter in baskets. Roads were clogged throughout the region with mudflows shutting down more than 30 miles (50 kilometers) of the 101 Freeway on Tuesday and knocking a number of homes from their foundations.